Both of my systems are apple, one has a Work Apple account and one has a Home apple account. How do I log into website X with 1 identity WITH FIREFOX? (people are going to jump through hoops when they find out my work laptop blocks mozilla services when I can just use a TOTP token on my phone and everything works.)

I think Firefox had system integration with the password/passkey provider framework since 122.

If you do not have access to your personal Apple account on your work laptop, you would need to find some other passkey provider with native integration.

Under Settings > Privacy and Security, look to see that Firefox is listed and has access under "Passkeys access for Web Browsers". Unlike a native app which only needs passkeys for its own services, Firefox needs access for every potential service you might hit over the internet.

Then under General -> Autofill and Passwords, you'll see any apps which are registered as system password managers. Unfortunately this is a subset of the ones which register on iOS and I'm not familiar who has done integration yet in their Mac release - Chrome (with GPM) for instance is not listed even though it is available on iOS.